[WIP] Allow using multipart/form-data to upload files with graphql

[jareks]

Currently sending multipart/form-data to Starlette's GraphQL results in 415 "unsupported media type" error.
This PR adds basic support for multipart/form-data which can be used for uploading files with GraphQL.

I am not sure if this is good way to implement this functionality and would greatly appreciate any comments. For what it's worth, this solution works fine in my pet project.

Regarding tests, I am happy to look into them once I get confirmation this PR goes in right direction.

[tomchristie]

Before proceeding with this - does the GraphQL spec support multipart uploads.
Could you link to any related or relevant docs so that I've got something to check the implementation against. Thanks! 😃

[jareks]

Here is the relay modern example is was starting with: facebook/relay#1844 (comment)
Please note this uses uploadables parameter of fetchQuery as described in Relay's network doc: https://relay.dev/docs/en/network-layer

I see second option: https://github.com/jaydenseric/graphql-multipart-request-spec
This spec seems to be a bit more complicated and I didn't need extra mapping functionality.

In summary: this PR adds very simple method to allow uploading files. Let me know if you think this is useful :)

[anilwarbhe]

Currently sending multipart/form-data to Starlette's GraphQL results in 415 "unsupported media type" error.
This PR adds basic support for multipart/form-data which can be used for uploading files with GraphQL.

I am not sure if this is good way to implement this functionality and would greatly appreciate any comments. For what it's worth, this solution works fine in my pet project.

Regarding tests, I am happy to look into them once I get confirmation this PR goes in right direction.

I am getting the same error 415. Need help on how to achieve file upload in starlette graphql.

Regards

[JayH5]

Thank you for creating this pull request. We have decided to deprecate GraphQL support within Starlette itself so I am going to close this pull request. See #619.